In the manufacturing process of a multilayer circuit board, because the multilayer circuit board includes multiple layers of core boards stacked together, a stacking disorder may easily occur during the stacking of the core boards, especially when the number of core boards is great. For example, a core board A intended to be placed in a first layer is placed in a fifth layer.
In the implementation of the present invention, the inventor finds at least the following defect in the prior art. If the stacking order of two core boards is incorrect, the electric network connection is usually normal, but the impedance or S parameter of the wiring may be affected. Therefore, when a signal is transmitted, signal abnormity may occur and crosstalk increases.